Can opener



C. S. MARDEN April 2, 1963 CAN OPENER 3 Sheets-Sheet 1 Filed Aug. 1. 1961 INVENTOR.

CARLTON S. MARDEN ATTORNEYS April 2, 1963 c. s. MARDEN 3,083,455

CAN OPENER Filed Aug. 1, 1961 3 Sheets-Sheet 2 FIG. 3

INVENTOR. CARLTON S. MARDEN C. S. MARDEN April 2, 1963 CAN OPENER 3 Sheets-Sheet 3 Filed Aug. 1. 1961 FIG. 8

FIG.7

INVENTOR. CARLTON S. MARDEN United States Patent M s,sss,4ss CAN OPENER Carleton S. Mai-den, 83 Revere t., Boston, Mass. Filed Aug. 1, 1961, Sen. N0. ras es 10 Claims. ((Il. 3ii9) The present invention relates generally to can openers, and more particularly to a device for severing the cover from a can by outwardly flaring the rolled rim of the cover while simultaneously severing the can from the mm.

The most common method for opening cans is to cause a circular cutting blade to roll about the annular inner side of the rim While severing the flat circular portion of the cover from the rim. This method is objectionable for several reasons. First, the cover may not be reapplied to the can. Second, the cutting blade penetrates the can and therefore comes into contact with the contents, which may result in contamination or objectionable odor or taste. It is frequently observed that particles of food remain upon the cutting blade after a can has been opened, and these particles may harbor bacteria and decay or mold. Such deleterious substances are then brought in contact with the contents of each successive can, unless the blade has been thoroughly cleaned and sterilized after each use. Third, the conventional method of opening a can leaves a severed cover with a sharp, generally jagged edge which is dangerous to handle, and which may readily fall into the contents of the can, with the result that the contents are further contaminated by the fingers and by any harmful substances present upon the exterior surface of the cover. Fourth, the cutting action frequently produces slivers or flecks of metal which fall into the contents of the can.

One of the objects of this invention is to provide a can opener which may be used to open cans which have been sealed in the ordinary manner, without bringing the cut ting blade into contact with the contents.

A second object is to provide a can opener which permits the severed cover to be reapplied to the can so that the can may continue in use for storage after the contents have been only partially used. As a related object, it is desired that the reuseable cover be safe and convenient to handle, with a minimum danger of contamination of the contents by foreign substances which may be present on its exterior surface.

A further object is to provide a can opener of simple construction and few parts which may be manufactured at a minhnum cost while insuring adequate precision and dependable action in use.

Other features of the invention reside in certain details of construction, modes of operation and arrangeents of the parts which will be more clearly understood by reference to the following description of a preferred embodiment thereof, having reference to the appended drawings illustrating the same, in which:

FIG. 1 is a side elevation of a preferred embodiment of the invention;

PEG. 2 is an opposite side elevation of the same embodiment;

PEG. 3 is a side elevation in section taken on line 33 of FIG. 1;

FIG. 4 is a fragmentary elevation in section of a can illustrating the snap action of a severed cover after it has been reapplied to the can;

FIG. 5 is a plan view in detail showing the relationship of the gauging wheel to the rim of the can;

FIG. 6 is an enlarged fragmentary side elevation in section similar to a part of FIG. 3 and showing a can in clamped position in the can opener;

FIG. 7 is a fragmentary elevation in section of a can sealed in a conventional manner; and

PEG. 8 is an elevation similar to FIG. 7 of the can after severance of the cover.

Referring to the drawings, a preferred embodiment of a can opener according to this invention is illustrated. The frame comprises two stamped sheet metal frame members 12 and =14 pivotally connected by a screw 16 threaded in the member il iand passing through a circular hole in the member 12. The member 14 is preferably folded about its upper edge as viewed in FIGS. 1 to 3 to form side walls mutually spaced by a distance slightly greater than the thickness of the member 12. One of the frame members, preferably the member 12, is provided with a mounting bracket 18 adapted to be fastened, as by wood screws 20, to a wall or other suitable support 22.

Bushings 24 and 26 are secured in the frame members 12 and 14, respectively. These bushings are grooved to receive a hairpin spring 26 which tends to separate them. it will be understood that the particular form of spring is a matter of choice, and that the form shown is only intended for purposes of illustration. As shown in FIG. 3, the member 12 is provided with a slot 30 to permit free movement of the bushing 26, and the member \14 is similarly provided with aligned slots 32 to permit free movement of the bushing 24'.

A clamp handle 34 is pivotally secured to the frame member 12 by a screw $6 threaded in the handle '34 and passing through a circular hole in the member 12. Preferably, this handle is formed of a sheet metal stamping folded about its upper edge as shown in FIGS. 1 to 3 and adapted to fit freely and overlyingly upon the folded edge of the member 14. The handle is further formed with shoulders 38 forming a pivotal end portion 40 of reduced thickness, the walls of which are fitted closely about the member 12, being spaced approximately the same distance apart as the walls of the member 14.

The frame member 14- is cut away in the region of the pivotal screw 36, thus providing a surface on the member 14 which abuts a fiat 41 on the handle when the latter is down as illustrated in full lines, and abuts a flat $2 on the handle when the latter is up as shown in broken lines in FIG. 1. FIG. 2 shows that the spring 2% constantly urges the member 14- firmly against one or the other of the flats on the handle.

A crank shaft 4:3 is rotatably secured in the bushing 26. A crank 44 provided with a boss at is secured to one end of the shaft 43 by a set screw 48 and provided with a handle 56. A gear 126 preferably having a knurled surface is secured in fixed relation to the shaft 43 adjacent the crank 44. The shaft 43 has a radially enlarged portion 52 of the same diameter as gear 126 at its other end, with the portion 52 having a cylindrical surface, the portion 52 forming a gauging wheel as hereinafter described. The surface of the wheel 52 may be smooth, if preferred, or provided with longitudinal serrations 53 as illustrated. A retaining disk 54 of somewhat larger diameter than the gauging Wheel 52 is secured to the latter by an axial screw 56. The disk 54 and the wheel 52 are precisely aligned axially by means of an annular shoulder 58 on the wheel 52 fitting within an annular recess 65} in the disk 54. The shoulder and recess may be tapered to facilitate alignment in a conventional manner, if desired. The screw 56 is secured by a lock washer 62 fitted between the head of the screw and a flat washer 66.

A cutter shaft 68 is received in the bushing 24 and has a gear 128 rigidly secured by suitable means to one end. This gear 128 is adapted to be interengaged with gear 12%. A radially enlarged portion 7i) forming a shoulder 72 adjacent the end of the bushing is provided at the other end of the shaft 68. A sleeve 74 having a set screw 76 is provided to retain the shaft 68 in the bushing. The

radially enlarged portion 71 of the shaft 68 forms a cutting wheel member which includes a circular cutting knife portion 78 and a gauging portion 81). The portion 80 preferably has a smooth cylindrical peripheral surface if the gauging wheel 52 has been provided with a smooth surface, or it has serrations 84 as illustrated (FIG. 6-) if the gauging wheel has been provided with the serrations 53. Intermediate the portions 78 and 81) of the cutting wheel member 70, the portion 73 has a conically tapered rim flaring surface 81.

Referring again to the clamp handle 34, it will be recalled that the pivotal portion 40 is provided with flats 41 and 42 alternatively engageable with the walls of the frame member 14 which restrain that member from upward movement in relation to the member 12, as viewed in FIGS. 1 to 3, thus opposing the force of the spring 28. The handle 34 has aligned saw cuts 88 and is preferably made of spring stock, heat treated for resilience. The dimensions are so chosen that a noticeable resilient deflection occurs in the handle at the saw cuts adjacent the flats 41 as the handle is lowered to the position shown in full lines and forces the gauging members 52 and 8% into contact, It will be appreciated that the resilient force exerted by the handle in its down position through its deflection at the saw cuts is appreciably greater than that of the spring 28 opposed to it, and therefore the gauging portions 52 and 80 remain in firm rolling contact until the handle is again raised. The flat 42 allows a predetermined upward movement of the member 14 in relation to the member 12, thereby allowing separation of the gauging members 52 and 80 under the force of the spring 28.

Referring again to the cutting wheel member 70, the radius of the cutting knife portion 78' is preferably machined so that it is spaced from the opposing surface of the gauging wheel 52 by approximately one thickness of the metal in the cover of a can to be opened when the gauging members 52 and 80 are fully engaged as described above. Also, the knife portion 78 has a chamfer 94 having a surface forming an angle with the vertical preferably in the range from 15 to 30 degrees as viewed in the drawings, the width of this surface being of approximately the same order of magnitude as the thickness of the metal in a can to be opened, preferably in the range from .009 to .013 inch. Radially inwardly of this chamfer, the cutting knife 78 is slightly relieved or cupped as shown at 96 to reduce interference with the can. Opposite to the chamfer the cutting knife has the generally conical surface 81 previously discussed, which forms an angle with the :axis of the cutter shaft 68 equal to that of the flare to be imparted to the rim of the can cover as hereinafter more fully described.

The operation of the can opener is as follows. Referring to FIG. 7, a can 100 to be opened is assumed to be of conventional construction and includes a generally cylindrical can wall 102 having a. longitudinal soldered seam (not shown) and a cover 104 secured to the can in a conventional manner to form a folded rim designated generally at 106. The portions of the cover 104 forming the rim include an inner wall 108 which has been slightly tapered outwardly toward the top in the canning machine to permit removal therefrom, an outer fold 110 and an intermediate fold 112. The portions of the can wall within the rim include an inner portion 114 and an outer portion 116 intermediate the folds 110 and 112 of the cover. The rim of the can is tightly compressed so as to form an effective seal, and if desired a small amount of sealant (not shown) may be compressed between the folds of the can and the cover according to a conventional method.

With the clamp handle 34 raised to a position 92 (FIG. 1), the can 100 is placed between the cutting knife 78 and the gauging wheel 52 with the retaining disk 54 lying inwardly of the rim 106 of the 'can. The clamp handle 34 is then lowered to the position shown in full lines in FIGS. 1 to 3, thereby bringing the gauging members 52 and 86 into firm rolling contact and causing the knife 78 to enter'the space between the intermediate fold 1-12 of the cover and the portion 114 of the can, flaring the folds 110, 112 and 116 outwardly against the surface 81 as viewed in FIG. 6. The knife 78 thereby penetrates the thickness of the can wall but does not sever the folds of the cover. The gauging member 52 firmly presses the top of the rim, thereby gauging the depth of the cut and insuring complete severance of the can from the cover. The angle of the conical surface 81 of the cutting knife determines the amount of flare imparted to the rim and the amount of flare is chosen to provide a reasonable tight fit when the severed cover is reapplied to the can. The interengagement of gears 126 and 128 limits the separation of gauging member 52 and knife 78 while the can is being cut, that might otherwise occur due to wear of bushings 24 and 26 or due to other reasons. The gears 12 and 128 also function to provide a more positive and uniform drive of shafts 43 and 68.

The application of pressure by the gauging wheel 52 downwardly against the rim of the can forces the inner fold 168 of the rim and the portion 114 of .the can outwardly against the chamfer 94, thereby producing a slightly flared edge 118 on the severed end of the can. The edge 118 serves at least three useful purposes: first, to hold the can ltltl in the can opener after the cover has been completely severed from the can; second, to turn the severed end of the can in a radial direction, thereby substantially reducing the danger of cutting the fingers during handling; and third, to provide a snap action feature when the cover is reapplied to the can, as hereinafter described.

In the initial closing action of the clamp handle 34, the retaining disk 54 is advanced to a position within the rim 106 of the can as illustrated in FIG. 6, whereby the disk 54 engages the rim at points 120 as shown in FIG. 5. Preferably, the disk 54 has a slightly relieved edge 7 adjacent the rim so that it will bear smoothly upon the slightly tapered inner surface of the fold 108 of the cover. i

The handle 50 is then turned and the cutting knife 78 is advanced about the annular rim 106 of the can. The rim is progressively flared and severed to produce a uniform cross section as shown in FIG. 8. It is found that the described embodiment accommodates the soldered longitudinal seam in the can with ease because of the clearances provided. As the handle 56 is turned the serrations 53 on the gauging wheel 52 biterinto the rim 106 of the cover and assist in rotating the can about its own axis thus feeding the rim into the operative flaring and cutting region between the gauging wheel 52 and the cutting knife 78. The serrations '53 also positively engage the serrations 84 on the gauging member and provide a positive drive for the cutting knife 78.

Thus it will be seen that the gauging members 52 and 8t) perform multiple purposes: to control the thickness of the cover which is not to be severed by the cutting knife, to provide a positive drive for the cutting knife and to provide a grip for driving the can.

After complete severance of the can from the cover, the can is held on the can opener by the pressure of the gauging wheelt52 downwardly on the portion of the cover which overlies the flared edge 118, forcing the latter against the chamfer 94, and in addition by the pressure of the disk 54 against the rim at the points 1211, which also forces the edge 118 of the can firmly over the chamfer 94. The severed can is easily removed from the can opener by lifting the clamp handle 34 to disengage the gauging wheel 52 and the retaining .disk 54 from the rim.

The edge 118 of the can after removal of the cover is smooth and is rendered safer to handle by'the flare imparted to it in the can opener.

To reassemble the severed can and cover, the parts are merely fitted together, and when compressed by the hand they fit neatly together and will positively engage one another With a snap action. This action is illustrated with reference to FIG. 4 and is described below. It will be appreciated that the scale of the parts has been exaggerated for purposes of illustration.

It will be evident that there are relatively large variations in the thickness of metal in different kinds of cans, which are of the order of 30 percent or even greater in certain instances. Certain tolerances are also permitted in the thickness of metal in a given can and in the concentricity of the cover and the can. Also, the process of opening the can as described results in some dimensional distortion of both the cover and the can, and the degree of distortion in different places may vary slightly according to any of the foregoing factors. Further, the handling of the can after removal of the cover is likely to result in a sli ht distortion thereof from the circular shape. Still further, the cover and the can are not ordinarily reassembled in precisely the same angular relationship as prior to removal of the cover. The result is that the can and the cover invariably fit with a certain degree of distortion of the rim of the can as the parts are pressed together. In certain places the can and the cover are spaced as depicted in FIG. 4, with the flared edge 113 on the can in interference with the inner periphery of the intermediate fold 112 of the cover. The continued application of pressure by the hand causes the rim lit; to snap into a recess 124- immediately above the fold 112. It will be appreciated that the amount of snap action is a function of the dimensions of the edge lift and the degree of flare imparted to the rim of the cover by the conical surface 81 on the cutting knife '78. In any case, sufficient snap action is obtained to cause the cover to fit securely upon the can and to resist any slight pressure tending to uncover the can accidentally. It will also be appreciated that in any case, the cover fits with sufiicient tightness upon the can to seal the contents effectively until ready for use.

It will be seen that numerous variations in the structure of particular parts of the can opener may be employed in accordance with techniques already known tothis art without departing from the spirit or scope of this invention, and that the illustrated embodiment is intended as illustrative. For example, while a crank handle 5% for manual operation has been shown, a motor drive of known construction may be employed. Also, suitable abutments may be attached to the frame members in order to assist in holding and aligning a can to be opened, as is common in the art. Furthermore, in place of serrations in the gauging members 52 and So it is possible to use gear teeth in accordance with designs well known to the gear making art.

Having thus described the invention, 1 claim:

1. A can opener having, in combination, a pair of mutually separable frame members, a gauging wheel pivotally mounted in one of said members, a cutting wheel pivotally mounted in the other of said members and having a blade portion and a gauging portion, both of said portions being opposed to said gauging wheel, means engaging said frame members and resiliently tending to separate said wheels, clamp means attached to one of said members and selectively engageable with the other of said members to urge said wheels together, whereby the ganging wheel and the gauging portion of the cutting wheel are held in rolling contact, and means for rotating the gauging wheel.

2. A can opener having in combination a pair of mutu ally separable frame members, a gauging wheel with a generally cylindrical surface pivotally mounted in one of said members, a cutting wheel pivotally mounted in the other of said members and having a blade portion and a gauging portion, both of said portions having circular periphery and being opposed to said surface, the blade portion having a radius smaller than that of said gauging portion by approximately one thickness of the metal in the cover of a can to be opened, means engaging said frame member and resiliently tending to separate said Wheels, clamp means attached to one of said members and selectively engageable with the other of said members to urge said wheels together, whereby the gauging wheel and the gauging portion of the cutting wheel are held in rolling contact, and means for rotating the ganging Wheel.

3. A can opener having, in combination a pair of mutually separable frame members, a gauging wheel with a generally cylindrical surface pivotally mounted in one of said members, a cutting wheel pivotally mounted in the other of said members and having a blade portion, a gauging portion and an oblique cover flanging surface intermediate said portions, both of said portions being opposed to said generally cylindrical surface, the blade portion having a radius smaller than that of said gauging portion by approximately one thickness of the metal in the cover of a can to be opened, means engaging said frame members and resiliently tending to separate said wheels, clamp means attached to one of said members and selectively engageable With the other of said members to urge said wheels together, whereby the gauging wheel and the gauging portion of the cutting wheel are held in rolling contact, and means for rotating the gauging wheel.

4. A can opener having, in combination, a pair of mutually separable frame members, a gauging Wheel with a generally cylindrical toothed surface pivotally mounted in one of said members, a cutting wheel pivotally mounted in the other of said members and having a blade portion, a toothed gauging portion and an oblique cover flanging surface intermediate said portions, both of said portions being opposed to said generally cylindrical surface, means engaging said frame members and resiliently tending to separate said wheels, clamp means attached to one of said members and selectively engageable with the other of said members to urge said wheels together, whereby the teeth of the gauging wheel and the gauging portion of the cutting Wheel are held in rolling contact, and means for rotating the gauging wheel.

5. A can opener having, in combination, a pair of mutually separable frame members, a gauging Wheel pivotally mounted in one of said members, a cutting wheel pivotally mounted in the other of said members and having a blade portion and a gauging portion, both of said portions being opposed to said gauging wheel, resilient means engaging said frame members and tending to separate said wheels, clamp means attached to one of said members and selectively resiliently engageable with the other of said members to urge said wheels together with a force greater than that exerted by said first-mentioned resilient means, whereby the gauging wheel and the gauging portion of the cutting Wheel are held in rolling contact, and means for rotating the gauging Wheel.

6. A can opener having, in combination, a pair of mutually separable frame members, a gauging wheel pivotally mounted in one of said members and having a gener-ally cylindrical cover engaging surface and a can retaining flange of larger diameter than said surface, a cutting Wheel pivotally mounted in the other of said members and having a blade portion and a gauging portion, both of said portions being opposed to said cover engaging surface, means engaging said frame members and resiliently tending to separate said wheels, clam-p means attached to one of said members and selectively engageable with the other of said members to urge said wheels together, whereby said cover engaging surface and the gauging portion of the cutting wheel are held in rolling contact, and means for rotating the gauging wheel.

7. A can opener having, in combination, a pair of mutually separable frame members, a gauging wheel pivotally mounted in one of said members, a cutting wheel pivotally mounted in the other of said members and having a blade portion and a gauging portion, both of said portions being opposed to said gauging wheel, means engaging said frame members and resiliently tending to separate said Wheels, clamp means attached to one of said members and selectively engageable with the other of said members to urge said wheels together, whereby the gan ing wheel and the gauging portion of the cutting wheel are held in rolling contact, and means for rotating the gauging wheel, said blade portion having a circular edge positioned to bear upon the side of a can and having a chamsfered annular edge adjacent the can.

8. A can opener for removing a can cover from a can comprising a gauging Wheel and a cutting wheel, said cutting wheel having a gauging portion and a cutting portion of smaller diameter than said gauging portion, both of said portions being opposed to and parallel with said gauging wheel, means supporting said wheels for movement toward and away from each other to and from a position in which said gauging wheel is interengaged with said gauging portion, and means for rotating said wheels when in said interengaged position.

9. A can opener for removing a can cover from a can comprising a gauging wheel and a cutting wheel, said cutting wheel having a gauging portion and a cutting portion of smaller diameter than said gauging portion, both of said portions being opposed to and parallel with said gauging wheel, means supporting said wheels for movement toward and away from each other to and from a position in which said gauging wheel is interengaged with said gauging portion, comprising parallel shafts each axially engaging one of said wheels, and support means supporting said shafts for selective movement toward and away from each other, a pair of gears mounted one on each of said shafts on the side opposite said support means to the side on which said wheels are mounted, said gears adapted to interengage when said gauging wheel is interengaged with said gauging portion, and means for rotating said wheels when in said interengaging position.

10. A device as set forth in claim 9 wherein said gears each have a diameter equal to the maximum diameter of the Wheel mounted on the same shaft.

Arnesen Apr. 9, 1940 Arnesen Sept. 9, 1941 

1. A CAN OPENER HAVING, IN COMBINATION, A PAIR OF MUTUALLY SEPARABLE FRAME MEMBERS, A GAUGING WHEEL PIVOTALLY MOUNTED IN ONE OF SAID MEMBERS, A CUTTING WHEEL PIVOTALLY MOUNTED IN THE OTHER OF SAID MEMBERS AND HAVING A BLADE PORTION AND A GAUGING PORTION, BOTH OF SAID PORTIONS BEING OPPOSED TO SAID GAUGING WHEEL, MEANS ENGAGING SAID FRAME MEMBERS AND RESILIENTLY TENDING TO SEPARATE SAID WHEELS, CLAMP MEANS ATTACHED TO ONE OF SAID 